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PVA(聚乙烯醇)改良膨胀土强度性能试验研究 被引量:1
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作者 文武 庄心善 +1 位作者 赵奕杨 聂去尘 《湖北工业大学学报》 2023年第1期90-93,共4页
PVA(聚乙烯醇)作为一种高分子聚合物,可利用其强粘结性改良膨胀土,提高改良土强度降低其膨胀性。通过三轴试验,研究不同PVA含量对膨胀土性质的影响,试验发现:围压相同时,随着PVA含量增大,改良土强度与内摩擦角呈先增大后减小的趋势;黏... PVA(聚乙烯醇)作为一种高分子聚合物,可利用其强粘结性改良膨胀土,提高改良土强度降低其膨胀性。通过三轴试验,研究不同PVA含量对膨胀土性质的影响,试验发现:围压相同时,随着PVA含量增大,改良土强度与内摩擦角呈先增大后减小的趋势;黏聚力先增大后趋于稳定。在相同围压下,当PVA含量为3%,膨胀土的主应力之差达到最大,3%为PVA的最佳含量。掺量相同时,PVA含量0%、1%、2%、3%、4%改良土条件下,围压300 kPa较围压100 kPa时,强度提高39%、36%、29%、32%、31%。 展开更多
关键词 膨胀土 pva(聚乙烯醇) 应力应变 抗剪强度
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聚乙烯醇离子交换纤维的制备和发展
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作者 逯阳 张华 《天津工业大学学报》 CAS 2005年第3期20-23,共4页
综述以PVA(聚乙烯醇)纤维为基体的离子交换纤维的制法,包括直接化学改性、缩醛交联引入活性基和脱水再功能化3种直接功能化方法和化学引发、物理引发两种接枝共聚功能化方法.并指出高强高交换容量离子交换纤维是今后发展的重点.
关键词 pva(聚乙烯醇) 离子交换纤维 功能性纤维
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PVA复合材料的研究进展 被引量:25
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作者 张琳琳 邵丽 +3 位作者 崔园园 冯超阳 张志斌 陈世龙 《化工新型材料》 CAS CSCD 北大核心 2010年第1期8-10,共3页
PVA(聚乙烯醇)是由聚醋酸乙烯酯水解而成的一种水溶性聚合物,具有强亲水性、优良的成膜性、可纺性好、并具有较好的力学性能,并且还不易受污染及突出的物理和化学稳定性,具有良好的生物降解性和生物相容性。本文综述了PVA在静电纺丝、... PVA(聚乙烯醇)是由聚醋酸乙烯酯水解而成的一种水溶性聚合物,具有强亲水性、优良的成膜性、可纺性好、并具有较好的力学性能,并且还不易受污染及突出的物理和化学稳定性,具有良好的生物降解性和生物相容性。本文综述了PVA在静电纺丝、相变材料和膜污染三方面的应用展开讨论。 展开更多
关键词 pva(聚乙烯醇) 静电纺丝 相变材料 膜污染
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Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺原位处理PVA废水及其沉淀物回收利用 被引量:2
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作者 郝昊天 韩昆 +1 位作者 石宝友 王毅力 《环境科学研究》 EI CAS CSCD 北大核心 2019年第2期340-346,共7页
为了评价Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA(聚乙烯醇)废水处理的可行性,采用Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺原位处理PVA模拟废水,考察不同作用时间、总铁投加量、初始ρ(PVA)和废水硬度对该工艺处理效果的影响.利用XRD(X射线衍射)、FT-IR(傅里叶... 为了评价Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA(聚乙烯醇)废水处理的可行性,采用Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺原位处理PVA模拟废水,考察不同作用时间、总铁投加量、初始ρ(PVA)和废水硬度对该工艺处理效果的影响.利用XRD(X射线衍射)、FT-IR(傅里叶转换红外光谱)、BET比表面积、VSM(磁滞回线测试)对沉淀物进行表征,解析该工艺原位处理PVA模拟废水的主要机理,并以该工艺沉淀物为吸附剂,通过锑吸附试验,探讨该工艺沉淀物的回用性.结果表明:(1)Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA模拟废水具有良好的处理能力,初始ρ(PVA)为1 000 mg/L时,该工艺在20 min以内即可达到80%以上的去除率,并且基本没有金属铁的残余,该工艺对PVA的去除率随总铁投加量的增加而提高且基本不受水体硬度影响.(2)在Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA的原位去除过程中,PVA作为一种反应物参与沉淀物Fe3O4的生成,并促进纳米Fe3O4比表面积增大,最终形成一种类似于凝胶的Fe3O4聚合物.(3)Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺可高效处理模拟PVA-MB(亚甲基蓝)染料废水.对于含有100 mg/L MB(亚甲基蓝三水)和500 mg/L PVA的混合溶液,MB和CODCr去除率在1 min时分别达到97. 37%和89. 47%.沉淀物通过磁分离、乙醇和水清洗后,在水中浸出的ρ(TOC)和ρ(CODCr)很低,分别为0. 86和2 mg/L,可作为吸附剂直接使用,得益于其具有较高的比表面积,对金属锑的拟合吸附量可达71. 94 mg/g.(4)Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺具有一定的实际应用价值.对东莞某实际印染废水处理5 min,CODCr和染料的去除率分别为85. 71%和98. 98%.研究显示,Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺可高效去除PVA,沉淀物为易回收的磁性Fe3O4,可作为吸附剂直接使用. 展开更多
关键词 铁氧体法 pva(聚乙烯醇) 四氧化三铁(Fe3O4) 原位处理 回收利用
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Wet Oxidation of PVA-Containing Desizing Wastewater 被引量:4
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作者 雷乐成 汪大翚 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第1期52-56,共5页
Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of ch... Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rate. Up to 90% of the initial CODcr was removed by wet air oxidation(WAO) at 270℃ with stoichiometric oxygen supply, while at temperature of 200℃, the CODcr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperature of 150℃. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. Initial solution pH was observed to play a significant role in PWAO and WPO where H2O2 was employed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODcr removal increases in the order: WAO, CWAO, PWAO and WPO. 展开更多
关键词 textile wastewater wet oxidation wet peroxide oxidation
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Characterization of Microcystis Aeruginosa immobilized in complex of PVA and sodium alginate and its application on phosphorous removal in wastewater 被引量:7
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作者 李飞 毛文娟 +4 位作者 李雪 王晓钰 肖智华 周耀渝 曾光明 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期95-102,共8页
Based on ecological niche theory, Microcystis Aeruginosa(MA) immobilized in the complex of polyvinyl alcohol(PVA)and sodium alginate(SA) crosslinked by CaCl2, was treated as a new kind of special species, and its prop... Based on ecological niche theory, Microcystis Aeruginosa(MA) immobilized in the complex of polyvinyl alcohol(PVA)and sodium alginate(SA) crosslinked by CaCl2, was treated as a new kind of special species, and its properties were investigated.Chlorophyll a was used to characterize the bioactivity of the immobilized MA. Results reveal that the gel beads have mechanical strength and chemical stability even under non-sterile harsh conditions, which may be attributed to the rarely seen structure(including three different layers: dense surface, tubular-shaped divergent structure and honeycomb crystal lattice layer) of the immobilized MA determined by scanning electron microscope(SEM). SEM also displays that more quantity of MA is attached to the inwall after cultivation, which demonstrates that the MA within beads maintains high bioactivity. Removal capacities on phosphorous(P) removal in wastewater in the presence and absence of the BG-11 medium were examined, and the removal ratios are 80.3% and76.7%, respectively, which indicates that the beads without providing ample nutrients still have high capacity of P removal. In addition, control experiment, utilizing polyvinyl alcohol and sodium alginate(PVA-SA) beads without immobilized MA,demonstrates that MA within beads plays the key role in absorbing P. 展开更多
关键词 eutrophication immobilized Microcystis Aeruginosa(MA) bioactivity phosphorous removal
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A Hybrid Dielectric Ink Consisting of up to 50 wt% of TiO2 Nanoparticles in Polyvinyl Alcohol (PVA)
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作者 Saumen Mandal Rahul Sharma Monica Katlyar 《Journal of Chemistry and Chemical Engineering》 2012年第7期625-630,共6页
PVA (Polyvinyl Alcohol) is a water soluble organic dielectric, easily solution processed to fabricate films by spin coating, dip coating or inkjet printing. It has been used as a dielectric layer in OTFTs (organic ... PVA (Polyvinyl Alcohol) is a water soluble organic dielectric, easily solution processed to fabricate films by spin coating, dip coating or inkjet printing. It has been used as a dielectric layer in OTFTs (organic thin film transistors), and its dielectric constant is around 3.5-10. For OTFTs operating at lower voltage, it is desirable to increase the dielectric constant. Here, we report a technique to incorporate upto 50 wt% of TiO2 nanoparticles (15-25 nm) in PVA to increase its dielectric constant. Rutile phase of TiO2 is used, because of its higher dielectric constant (e = 114) compared to anatase phase (E = 31). We have made inks containing 10 and 50 wt% (of PVA) TiO2 nanoparticles, which is stable upto six months. PVA-TiO2 dispersions and PVA (without TiO2) were spin coated on indium tin oxide coated polyethylene terephthalate substrate. Film structure was studied using SEM (scanning electron microscopy). Absorption study of the films confirms presence of TiO2 nanoparticles. M-I-M capacitors were fabricated by thermally evaporating aluminium on top of the dielectric films. We observed enhancement in dielectric constant by a factor of 2 for PVA containing 50 wt% TiO2 in comparison to PVA's dielectric constant. There is no concomitant increase in the leakage current. 展开更多
关键词 Dielectric constant organic dielectric titanium dioxide NANOPARTICLE polyvinyl alcohol low voltage operation.
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Preparation and swelling behavior of polyvinyl alcohol physiological saline gel 被引量:2
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作者 潘育松 熊党生 马如银 《Journal of Central South University of Technology》 EI 2006年第1期27-31,共5页
Polyvinyl alcohol(PVA) physiological saline gel was prepared using physiological saline solution of the polymer by freezing and thawing method. The influences of the concentration of PVA, freezing and thawing cycle ti... Polyvinyl alcohol(PVA) physiological saline gel was prepared using physiological saline solution of the polymer by freezing and thawing method. The influences of the concentration of PVA, freezing and thawing cycle times and solvent swelling media on the swelling properties of PVA saline gel were investigated. The result show that the electrolytical ions have great effect on the swelling behavior of PVA saline gel. The equilibrium swelling ratio of PVA saline gel in aqueous swelling media is larger than that in saline swelling media. Also, the equilibrium swelling ratios of PVA saline gel in aqueous and in saline media decrease with the increase of gel concentration and the increase of freezing and thawing cycle times. The decreasing speed of equilibrium swelling ratio with the increase of freezing and thawing cycle times of PVA gel in distilled water is faster than that in physiological saline. The swelling kinetic equation can sufficiently describe the swelling behavior of PVA physiological saline gel. 展开更多
关键词 freezing and thawing polyvinyl alcohol saline gel swelling behavior
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Tensile properties of strain-hardening cementitious composites containing polyvinyl-alcohol fibers hybridized with polypropylene fibers 被引量:3
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作者 H.R.Pakravan M.Jamshidi 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第1期51-59,共9页
Partially replacing polyvinyl-alcohol(PVA)fibers with polypropylene(PP)fibers in strain-hardening cementitious composites(fiber hybridization)modify certain mechanical properties of these materials.The hybridization b... Partially replacing polyvinyl-alcohol(PVA)fibers with polypropylene(PP)fibers in strain-hardening cementitious composites(fiber hybridization)modify certain mechanical properties of these materials.The hybridization based on the introduction of low-modulus hydrophobic polypropylene fibers improves the ductility and the strain-hardening behavior of the cementitious composites containing polyvinyl-alcohol fibers of different types(PVA-SHCC).Pull-out tests indicate that adding PP fibers increases the energy capacity of the hybrid composite with respect to the material containing only PVA fibers under tensile loading,and PP-fiber geometry(i.e.,section shape and length)is a key factor in enhancing the strain capacity. 展开更多
关键词 polyvinyl-alcohol (pva) strain-hardening cementitious composite (pva-SHCC) fiber hybridization
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